gulpfile.js

var gulp = require('gulp');
var sass = require('gulp-sass');
var rename = require('gulp-rename')
var changed = require('gulp-changed')
var watcher = require('gulp-watch')

//自动监听
gulp.task('default', gulp.series(function () {
    watcher('./pages/**/*.scss', function () {
        miniSass();
    });
}));


//手动编译
gulp.task('sass', function () {
    miniSass();
});


function miniSass() {
    return gulp.src('./pages/**/*.scss')//需要编译的文件
        .pipe(sass({
            outputStyle: 'expanded'//展开输出方式 expanded 
        }))
        .pipe(rename((path) => {
            path.extname = '.wxss'
        }))
        .pipe(changed('./pages'))//只编译改动的文件
        .pipe(gulp.dest('./pages'))//编译
        .pipe(rename((path) => {
            console.log('编译完成文件：' + 'pages\\' + path.dirname + '\\' + path.basename + '.scss')
        }))
}